Indeed, opping everyone is fairly ridiculous. Even if you are an IRC Operator, or have ChanServ to help prevent channel takeovers, why would you bother putting everyone (or some people) through the inconvenience of being kicked out all the time?
Nevertheless, if that's what you want, it's your channel and really you can do what you like with it (except if it breaks network rules as Locutus pointed out).
Slartibartfast pointed out that if you're planning to op someone when they join the channel, why not just preset an AOp mask that encapsulates "everyone" rather than wasting time checking if they're an AOp or not and then adding them? And what way do you want them to be added as an AOp?
If you're in the channel 24/7, then simply use
/aop * #channel and you'll auto-op everyone who joins.
Ask in the #Help channel on the network you use, or contact an IRC Operator, to find out if it's against rules to add *!*@* to chanserv - as mentioned, it is on DALnet, as you can see
here.
To put it in a simple script (which is not necessary, but just an FYI) you'd use something like:
on @*:join:#channel:{ mode # +o $nick }
and change #channel for the channel name. Due to the /aop command however, it's not necessary to make a remote file for it.
Hope this has been informative
Regards,